In most cases, a Reactor Model input file is written by the Ansys Chemkin Interface before a simulation run based on the Chemkin Project Input. The panel context and "bubble" help within the Interface provide basic guidance for setting up model-specific input parameters. However, in some cases users may want further information about a model parameter usage and in other cases they may want to assemble their own input files outside of the User Interface. For such cases, this chapter together with Reference Guide to Project Input Keywords and Alphabetical Listing of Project Input Keywords contain detailed information about input options for each Reactor Model. This chapter provides an overview of the syntax and rules for such parameter input.
User input information is generally written to a Reactor Model input file in "keyword" format. In this format, each input line starts with an identifying keyword. For some input, only the keyword itself is required, while others require one or more pieces of additional information. Many keywords have default values associated with them. If these default values are appropriate for the user’s problem, then these keywords do not need to be included in the input file. In the case of restarts or continuation problems, some of the parameters can be changed from what was used in the previous solution. If these keywords are not included or not changed in the input keyword list for continuations or restarts, then the parameters will retain their former values. In the list of keywords that follow, we indicate whether or not each keyword may be changed on a restart from a previous solution. The order of the keyword input is not important. The general rules governing the syntax of the keyword lines are listed in Table 8.1: Summary of the Rules for Keywords.
Note: Note that you can turn on or off the display of the "Keyword" associated with an Ansys Chemkin Interface input parameter, using the modal option in the Preferences panel.
Table 8.1: Summary of the Rules for Keywords
Rule | Description |
|---|---|
1 | The first character-string in the line must be a keyword; the length of the character-string depends on keyword descriptions. |
2 | Any further input associated with the keyword can appear anywhere after the keyword, through column 80. The specific starting column is not important, as long as there is at least one space after the keyword. |
3 | When more than one piece of information is required, the order in which the information appears is important. |
4 | When numbers are required as input, they may be stated in integer, floating-point, or "E" format. Ansys Chemkin converts the numbers to the proper type internally. The double precision specification D is not recognized; however, the double precision conversion will be done internally, as necessary. |
5 | When species names are required as input, they must appear exactly as they are specified in the Gas-phase Kinetics and Surface Kinetics input files. |
6 | When more than one piece of information is required, the pieces are delimited by one or more blank spaces. |
7 | If contradictory or duplicate keywords are input, Ansys Chemkin uses the information that is last read. Under some circumstances, this will result in a warning printed to the output file. |
8 | A "comment" line is one that has either a period ( |
9 | The keyword |
10 | If no parameter is given, then the keyword stands alone on the input line; keywords with parameters are demonstrated with examples. |